Without limiting the scope of the invention its background is described in connection with an electronic calculator having math graphing capabilities and memory means for storing data and functions. It should be understood, however, that principles disclosed may also be used in other applications such as desktop computers, portable notebook computers and other similar computing devices.
Educational institutions, businesses and individuals depend on electronic computing devices such as computers, calculators and organizers to store, analyze and manipulate information. One such device, the electronic calculator, has proven to be a very useful tool in a number of applications. For example, calculators are commonly used in business applications to prepare financial statements including balance sheets and income statements, and in reconciling balances. Also, calculators are used for engineering applications such as solving equations for stress and strain, resistance and voltage, or chemical concentrations. Further, calculators are commonly used for personal applications such as balancing checkbooks and home budgeting.
In addition, calculators are commonly used in educational applications. Not only are calculators useful for solving mathematical problems, but also, calculators have recently become effective teaching devices. Several developments in calculator technology have enhanced the teaching capabilities of calculators. For example, the incorporation of a screen into the calculator which allows the user to view not only, the answer, but also the formula or equation inputted by the user.
Additionally, calculator screens have enabled the calculator to present graphical data, which is particularly beneficial in teaching applications. This capability allows a user to enter a function or data from an experiment and view the function or the data in a graphical format. The user may then, for example, change a parameter within the formula or the data to see its effect on the graph.
These calculators often have the capability of graphing in a variety of modes. For example, an equation can be graphed as a function of two rectangular variables in the form y=f(x), two polar variables in the form r=f(.theta.), or three parametric variables in the form x=f(t) and y=g(t). Some of these calculators also have the capability of determining the vector or (x,y) coordinates of a data point along a graph. With such calculators, a user can position a cursor at a given point or points on a graph or functions and resolve the vector coordinates of the point or points.
These calculators, however, limit the user's ability to study, analyze and edit such data in other applications. For example, should a user wish to collect a series of points and import them into a matrix, list or other similar application, he or she must resort to resolving the individual points one at a time and then inputting into a separate application manually. Calculators with built in scientific, engineering and statistical applications lack a quick method of transferring data between different applications resident to the calculator for further study and analysis by the user.
Thus, what is needed is a way to capture data from a graph or screen image and transfer the data to one or more internal applications for further analysis.